1. Field of the Invention
This invention is in the field of vehicle parking boots which are useful for preventing unauthorized driving of a motor vehicle.
2. Description of the Prior Art
Various devices have been used or proposed for immobilizing vehicles from unauthorized movement, the most successful of which has been the lightweight device described and claimed by me in U.S. Pat. No. 4,854,144 of Aug. 8, 1989.
Other wheel locking devices, some of which are known as "Denver Boots," are shown in the references cited in my prior, aforementioned patent application.
My prior patented device has an adjustable arm which slides in a housing to open and close the device for application and removal, which locks in the immobilizing position, and which is interconnected to two articulating arms which traverse the tire tread and engage the inside of the tire in the immobilizing position. While said device has been commercially successful, due to the interconnection between the adjustable arm and the articulating arms, when said device is applied to different size tires, the angle between the three arms when the device is in the locked position is different, i.e., for larger tires, the angle between the "left" ("upper") and "right" ("lower") articulating arms is greater than 120 degrees, whereas for smaller tires, the angle turns out to be substantially less than 120 degrees because the adjustable arm does not extend as far as with normal or larger tires. I have found that as close to 120 degrees as possible is preferred because the device is less secure against unauthorized removal when the arms are at other angles.
The problem in the art has been that no one has proposed or used a device which is light weight, very secure, quick to apply, and yet useful for a very wide range of tire sizes.